Such meters need to be read regularly in order to determine the amount that has been consumed, in particular for billing purposes. In conventional manner, a technician reads a meter by visiting the premises where the meter is installed. However, it is sometimes difficult to gain access to a meter, for example when the meter is installed in private premises and the occupier is not present when the technician calls. In addition, visiting each person having a meter slows down the operation of reading meters.
That is why systems for reading meters remotely have been developed that enable an operator traveling in a given geographical zone to read the meters situated in that zone remotely. In another type of configuration, the meters communicate with a fixed receiver within the zone in question.
The main types of communication implemented are radio communications or wire communications (a cable network). Each meter in a zone is provided with a transmitter or a transceiver, often referred to as a “communications module”, that is suitable for communicating with a receiver or a transceiver, often referred to as a “terminal” or a “concentrator”, and which may be stationary or mobile within the zone in question.
The communications module transmits the information it has to send concerning the meter to which it is connected either in response to an interrogation signal transmitted by the terminal, or else substantially periodically. The terminal receives this information which is then processed, e.g. for statistical or billing purposes.
As a general rule, the communications link is tested during installation. However such tests need to be performed by competent technicians since they implement sophisticated apparatuses that are different from those used subsequently in remote meter-reading operations.
In addition, even if a link is cleared during testing, there is no guarantee that the link will not deteriorate as its electronic components age, or as weather or other conditions surrounding the meter change, etc. For example, it is known that the performance of radio transmitters varies as a function of temperature. A link that was tested in summer and found to be satisfactory can fail in winter. Or indeed the operation of a communications module can be disturbed if its environment is changed: moving a domestic appliance close to a meter situated in a kitchen, for example, can cause a link to become unusable.
It is therefore desirable to be able to quantify the quality of the communications link of each communications module. When the operating margin is sufficient, it can be expected that the communications link will suffice even in the event of disturbance appearing such as the aging of electronic components, a change of temperature, a change of environment, etc.
However, it is also desirable to perform such measurements without it being necessary to visit each communications module and without it being necessary to implement sophisticated and expensive measurement equipment.